Dstv cant fix a technical problem for 6 months now

I work for a business. On 1 Nov 2018 we recieved an invoice for certain amount. Debit order amount was not the same as invoice amount.

Every time I phone DSTV Business, they say they are experiencing technical problems with credit notes.

How in the world can a big Company like DSTV not be able to fix a common accounting technical problem within 6 months. We need proper documents for auditing purposes, and DSTV can't fix a technical problem - FOR 6 MONTHS.

Ridiculous.